硅酸盐学报2025，Vol.53Issue(12)：3476-3483,8.DOI:10.14062/j.issn.0454-5648.20250442
直径6英寸YSZ:Er晶体生长与光谱
Growth and Spectra of 6-inch YSZ:Er Crystals
摘要
Abstract
Introduction Lasers operating within a spectral range of 1.5-1.7 μm are essential for eye-safe applications like laser ranging,lidar,and optical communications,etc..Nevertheless,conventional laser crystals such as Er:YAG and Er:LuYO3 have limitations in emission cross-sections or attainable crystal dimensions,thereby constraining their utilization in high-power,large-scale laser systems.To address these challenges,the development of novel laser crystals with substantial crystal sizes and high emission cross-sections is thus imperative.Yttria-stabilized zirconia(YSZ)doped with rare-earth ions emerges as a promising candidate due to its disordered crystalline structure that enables a broader wavelength tunability and a reduced thermal loading under resonant pumping conditions.Specifically,erbium(Er3+)doped YSZ crystals have a significant potential due to its intense emission at 1.5 μm(4I13/2→4F15/2 transition)for eye-safe laser.This study was to investigate the growth of large-scale Er3+-doped YSZ crystals by a skull melting technique,and the optical and spectral properties were systematically investigated to explore a novel laser gain medium in the infra-red region. Methods Pure YSZ and Er3+-doped YSZ crystals(i.e.,0.36%,1.60%and 2.54%in mole)were grown by a skull melting method(or a cold crucible technique),and a radio frequency(RF)generator was used to heat up the charges.A large-scale furnace with a diameter of approximately 150 cm was employed to accommodate the spontaneous nucleation.Graphite electrodes were used for initial arcing due to the poor conductivity of ZrO2 at<1200℃.At>1200℃,raw materials became an electric conductor to form the melting pool.The lowering mechanism started to work at a lowering rate of 2 mm/h,and the melt crystallized from the bottom to the top.After the growth,annealing process was performed to release the internal stresses.The phase and crystal structures of as-grown crystals were characterized by X-ray diffraction(XRD).The transmittance and absorption properties were analyzed by UV-Vis-NIR spectroscopy.The luminescence and decay curve were also systematically evaluated. Results and Discussion The results show that Large-sized YSZ and Er-doped YSZ crystals with the diameters and lengths of exceeding 150 mm(6 inches)are grown,representing the largest YSZ single crystals reported.The XRD patterns indicate the cubic structure with a preferred<111>preferred orientation.The lattice parameters increase slightly with Er3+concentration,indicating the effective incorporation of Er3+into the YSZ lattice.The transmission of exceeding 74%in the range of 400-1650 nm occurs for pure YSZ crystals,confirming relatively high crystalline qualities.The absorption spectra for Er-doped crystals show some characteristic peaks at 378,408,451,489,518,546,654,971,1460 nm and 1530 nm,corresponding to Er3+transitions from the ground state 4F15/2 to excited states such as 4G11/2 and 4F11/2.The most intense absorption band occurs at 971 nm,which is attributed to the 4F15/2→4F11/2 transition.Under 971 nm excitation,the emission spectra exhibit a dominant peak at 1530 nm for the 4I13/2→4F15/2 transition,which is ideal for eye-safe lasers.The great emission intensity appears at an Er3+mole concentration of 1.60%,with an emission cross-section of 4.811×10-20 cm2,which is significantly higher than that of Er:YAG(i.e.,0.6×10-20 cm2)and Er:LuYO3(i.e.,0.261×10-20 cm2).Correspondingly,the decay time of YSZ:0.36,YSZ:1.60and YSZ:2.54 crystals is 1.836 ms,1.149 ms and 0.797 ms,respectively. Conclusions This study demonstrated the effective growth of large-scale(6-inch)YSZ and Er-doped YSZ crystals by a skull melting method.YSZ:Er crystals exhibited an intense emission at 1530 nm under 971 nm excitation.In particular,a high emission cross-section of 4.811×10-20 cm2 and suitable fluorescence lifetime of 1.149 ms appeared for Er3+of 1.60%in mole.YSZ:Er crystals could be used as a highly promising gain medium for high-power,eye-safe lasers at 1.5 μm due to the ultra-large crystal size and relatively large emission cross-section.关键词
钇稳定立方氧化锆/冷坩埚法/晶体生长/激光晶体Key words
yttria-stabilized zirconia/skull melting method/crystal growth/laser crystal分类
数理科学引用本文复制引用
CHEN Yuxuan,JIANG Xin,SHEN Hui,TIAN Tian,JIANG Zefeng,XU Jiayue..直径6英寸YSZ:Er晶体生长与光谱[J].硅酸盐学报,2025,53(12):3476-3483,8.基金项目
国家自然科学基金(51572175). （51572175）
